SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5037cef1a65615fcd7bb5e5a147bd30987571594980a1bbf6485966cc09f7aab' 
  AND token = 'YUEfYEfQ8j4416Ul157tBsc/eVqobBlA7i8KUw3i/FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}